Longitudinal Element, in Particular for a Traction or Suspension Means

ABSTRACT

A longitudinal element produced with a core made of high-strength fibers and at least one metal casing, preferably steel, surrounding this core. In this way, there is the significant advantage that these high-strength fibers, which are very lightweight in relation to their strength, are protected in a number of ways, namely against humidity, moisture, UV light and other environmental influences. In addition, the metal casing provides the fibers with protection against transverse loads. In this way, all the high-strength properties of the traction or suspension means are maintained over a sustained period

The invention relates to a longitudinal element, in particular for atraction or suspension means, according to the preamble of claim 1.

A combined line-shaped traction and/or suspension means as in citationEP-A-2 165 017 discloses a core line of high-strength plastic fiberswhich is made from a twisted monofilament bundle or a plurality ofdrilled monofilament bundles and made with an outer layer of steel wirestrands. The monofilament bundle is stretched while reducing thediameter and held in this condition by a, particularly woven, casing.This reduces the core line stretching under load so that the loaddistribution between the steel cross-section and plastic cross-sectionof the line is improved.

And conversely in the same sense, to approach the stretch behavior ofthe strand layer compared with that of the core line, the line has anintermediate layer of an elastic plastic into which the steel wirestrands are impressed spaced separately from one another so that theouter layer stretches under load and contracts radially.

Making such a combined line is relatively expensive; nor is it protectedsufficiently against the prevailing environmental influences inoperation such as humidity, moisture etc.

Nets known as annular nets or meshes stand out for being highlytear-resistant and deformable and can therefore be stressed to aconsiderable extent. According to citation EP-B-0 979 329, such aprotective net is known as a high-strength wire mesh preferably forrockfall protection or to secure a surface layer of earth which is wovenfrom coil-shaped bent high-strength steel wires and has athree-dimensional structure. The coil-shaped bent wires have a helixangle and length between two bends which govern the shape and size ofthe slots in the wire mesh.

The present invention on the other hand was based on the problem ofcreating a longitudinal element in particular for traction or suspensionmeans for different applications such that this shows similarcharacteristics to a longitudinal element made of wires which optimizesthe weight whereby it should work perfectly well even under harshenvironmental conditions.

According to the invention, this problem is solved by thecharacteristics of claim 1.

Instead of from wires, the longitudinal elements made with a core of aplurality of high-strength fibers are each made of at least one metalcasing surrounding this core, preferably steel.

Advantageously, the metal casing of the longitudinal element concernedis attached to the outside circumference of the core in such a way as toform a gas-tight, UV-tight, light- and/or water-impermeable layer forthese fibers.

This has the considerable advantage that these high-strength fiberswhich are very light in relation to their strength are protected in manyrespects, particularly against humidity, moisture, UV light and otherenvironmental influences and also by being bound to the metal casingstretch to approximately the same extent. The metal casing also protectsthe fibers against transverse loads: so the high-strengthcharacteristics of the traction or suspension means remain sustainablyas a whole.

One of the significant advantages of this embodiment of the wire-shapedlongitudinal elements is that it is suited to a plurality ofapplications.

They may be used as longitudinal elements in nets, meshes, gratings orsimilar for protection, safety, aquaculture or architectural purposes,for example.

These longitudinal elements are just as suited to traction or suspensionmeans such as spiral or stranded wires, prestressed lines or the like,particularly in funicular lines and transport. These longitudinalelements may be used with both running and standing line constructions.

On the other hand, these longitudinal elements may also be used inelectrical cables, telecoms cables or lines, ensuring they will operatepermanently perfectly even under harsh environmental conditions.

Other applications of such wire-shaped longitudinal elements are alsopossible within the scope of the invention which require high tensileforces and/or a high degree of environmental resistance at low weight,advantageously while having a bending effect at the same time. Theselongitudinal elements may also be used lying parallel to one another,i.e. not braided.

Embodiments and other advantages within the scope of the invention willbe explained more particularly with the aid of a drawing below. Theseshow as follows:

FIG. 1 is a perspective part view of a longitudinal section withcross-section;

FIG. 2 is a cross-section of a traction and/or suspension means made asa spiral line with braided longitudinal elements as in FIG. 1;

FIG. 3 is a cross-section of a traction and/or suspension means made asa braided line as in the invention,

FIG. 4 is a cross-section of a traction and/or suspension means made asa sealed line as in the invention;

FIG. 5 is a cross-section of a telecoms line with wire-shapedlongitudinal elements as in the invention;

FIG. 6 is a cross-section of an electrical cable with wire-shapedlongitudinal elements as in the invention;

FIG. 7 is a cross-section of another variant of an electrical cable withintegrated wire-shaped longitudinal elements;

FIG. 8 is a partial view of a net shown as a mesh woven as twistedlongitudinal elements as in the invention;

FIG. 9 is a partial view of a safety net for the protected area made ofinterlocking annular longitudinal elements;

FIG. 10 is a cross-section of a ring in the net made of a longitudinalelement as in FIG. 9;

FIG. 11 is a part view of a mesh made of longitudinal elements as in theinvention, and

FIG. 12 is a cross-section of a variant of a longitudinal element as inthe invention.

FIG. 1 shows a longitudinal element 13 which can in particular absorbtensile forces and/or loads even at very high forces. It may be used ina wide range of applications, as the embodiments below will show.

According to the invention, this longitudinal element 13 made as a wirecomprises a core 12 of a plurality of high-strength fibers 11 and ametal casing 15 surrounding this core 12 preferably made of steel and/orstainless steel.

Metal casing 15 is arranged around core 12 formed of fibers 11 and alongthe longitudinal extent of longitudinal element 13 and held for exampleby a welded seam 15′ at the butted surfaces of the side edges.

Welding metal casing 15 in this way gives a gas- and watertight coatingfor these fibers 11, sealing them away from UV light and the atmosphere,extending their working life while maintaining almost the same strengthpractically without ageing them. This may be increased even more if themetal casing is made of stainless steel.

Metal casing 15 is given a certain bending and/or buckling strength toachieve a suitable flexibility and/or sufficient shock- and/or pressureresistance of the longitudinal element.

The metal casing may be given a variable casing cross-section along itslongitudinal extent; likewise different kinds of high-strength fibers 11may be used to obtain an optimum design to meet the differentrequirements of the specific applications concerned.

The metal casing may consist of a second and/or more casing layers. Toachieve the variable cross-section, at least a second casing layer maybe applied to a first casing layer including for specific distances.

A further characteristic of the invention is that metal casing 15 ismade with a cylindrical outer surface. This outer surface may be shapeddifferently as required, of course.

Advantageously, a filling layer 14 may be inserted between metal casing15 and core 12 of the wire-like element concerned, such as a gel oradhesive, for example, a bandaging or a mixture thereof. Depending onthe application, a different degree of hardness of the filler layer maybe used to obtain different transverse loads and tensile characteristicsof the longitudinal element. This may be used to design the degree ofattachment created in the finished longitudinal element differentlydepending on the application to optimize its transverse load strength.

The metal casing and/or core may be given a surface roughness to give abetter connection between fibers 11 and the inside of metal casing 15 byfriction and/or adhesion to give a nearly even tension/extensionbehavior.

The metal casing could also preferably be made as a tube into which thefibers could be inserted.

The metal casing could equally well be made by winding at least onemetal strip around the core which could be joined at the overlappingand/or abutting side edges by welding, gluing or a similar connection oreven without any such. A suitable material for the metal casing would bea corrosion-resistant material such as a galvanized steel but alsoaluminium or copper with non-corroding characteristics.

The high-strength fibers may be made of plastic fibers, for example,such as aramid (Twaron 2200) and/or carbon fibers such as carbon fibersor basalt fibers which have a tensile strength of over 2,000 N/mm².Other materials with similar characteristics could of course be used,such as HMPE and/or high-modulus polyethylene fibers (Dyneema) orsimilar. So-called basalt fibers and/or fibers of a mixture of plasticand basalt or another mineral additive could be used. The fibers may bearranged parallel to one another or twisted.

At least a part of the high-strength fibers could also be made of steelfibers (steel cords) which preferably have very small diameters such as0.4 mm and a tensile strength preferably over 2,500 N/mm²; but materialsother than fibers are also possible which have tensile strengths over2,000 N/mm².

Core 12 made of high-strength fibers, steel cords and/or other materialsis dimensioned with an outer diameter preferably from 1.5 to 8 mm,equivalent more or less to the diameter of an ordinary wire.

The wall thickness of the metal casing is preferably between 0.1 and 1.0mm, whereby for this a steel of over 800 N/mm² and advantageously ahigh-strength steel with a strength of over 1,000 N/mm² is used.

FIG. 2 shows a spiral line 10 which is composed of conventionally linedlongitudinal elements 13. Such a spiral line 10 is suited above all as astop, signal or tension relief line which is used for example to stop,destress and/or to transmit energy and/or data. It may also be used as acarrying line or as a line for funicular railway cabins running on it,however.

It could also advantageously be used as a pre-stressed strand inparticular for static constructions such as a roof structure in whichlongitudinal elements 13 are laid next to one another without beingstranded or would only be wound slightly.

According to the invention, longitudinal elements 13 made as wire aremade in each case of a core 12 of a plurality of high-strength fibers 11and of at least one metal, preferably steel, casing surrounding thiscore 12.

FIG. 3 shows a braided line 20 as a traction or suspension meanscomprising multiple strands 21 wound around a plastic core 22.

According to the invention, individual strands 21 are made by windingwire-like longitudinal elements 23, 24 each of which is made of a core26, 27 of a plurality of high-strength fibers 28, 29 and of at least onemetal casing 25, 35, preferably steel, surrounding this core 26, 27.

Otherwise, these longitudinal elements 23, 24 are made in the same wayas those in FIG. 1 and/or FIG. 2 and will therefore not be dealt with inany further detail.

Advantageously, all longitudinal elements 23, 24 of a braid 21 are madeas in the invention; but individual longitudinal elements such as theinnermost may also be made of a steel wire.

FIG. 4 shows a sealed spiral line 30 as a traction or suspension meansin which longitudinal elements 31 at the outer circumference or in otheradditional layers are provided by a known means with a Z-shaped[cross-section] while inner longitudinal elements 32 have a roundcross-section.

According to the invention, these Z-shaped longitudinal elements andinner ones 31, 32 as well are made in each case of a core 33, 34 of aplurality of fibers 36, 37 and of at least one metal, preferably steel,casing 38, 39 enclosing this core 12, wherein these fibers 36, 37 areshown only for one longitudinal element but all are advantageously madein this way.

As a particular feature of the invention, these Z-shaped longitudinalelements 31 are each made with an appropriately shaped metal casing 39in which this approximately Z-shaped core 33 with fibers 36 iscontained. Instead of these Z shapes, I, wedge- or other shapedlongitudinal elements may be used.

The metal casing is made advantageously of or coated with acorrosion-resistant material such as stainless steel. It may also bemade of two or more layers, however.

The outer circumference of the steel casing could be made withappropriate openings for wires and/or strands or the like.

Also, continuous or multiple braces laid one after another or similarcould be arranged within the metal casing which would increase itsrigidity. The surface of the individual longitudinal elements could beoptimized in terms of surface design and/or roughness to interact withone another.

The surface of the cores of high-strength fibers should be made suchthat the core makes an optimum connection with the casing in terms ofmodulus of E and strength but no excessive loads arise in the fibers incontact with the casing.

FIG. 5 shows a diagram of a cross-section of a telecoms line 50 which ismade in a per se conventional way from conductors 51, 52, 53 in multiplelayers by braiding. Individual conductors 51, 52, 53 may be made ofindividual wires or wire strands surrounded by an insulating casing ineach case. At least one conductor 54 is also integrated with the innerlayer of line 50 which is provided for communication purposes orsimilar.

According to the invention, a number of wire-shaped longitudinalelements 56 are integrated in line 50 which consist in each case ofthese high-strength fibers and this surrounding metal casing which isnot shown in more detail. The two outer layers here are alternately aconductor 52, 53 and neighboring longitudinal element 56. Thedistribution of the conductors and/or longitudinal elements could alsobe selected differently, of course, depending on how strong line 50 mustbe.

FIG. 6 shows a cross-section of an electrical cable 60 as in theinvention in diagram form the inside of which comprises a conventionalsingle- or plural conductor 61 with casing 62 and copper conductors 63with insulation. This conductor 61 is shrouded by two layers oflongitudinal elements 64 with high-strength fibers 66 and metal casing65 surrounding them.

FIG. 7 shows a further variant of an electrical cable 70 incross-section, comprising a casing 73, a number of insulated copperconductors 71 or the like and longitudinal elements 74 integratedtherewith. The latter with high-strength fibers 76 and casing 76surrounding these are appropriately of the same outer diameter as copperconductors 71 so these may be braided together. Three longitudinalelements 74 are arranged woven around the central copper conductor 71and three between these copper conductors 71 arranged in each case. Withthis electrical cable 70 also, differences may be provided in the numberand arrangement of these longitudinal elements.

Of course, still other variants of telecoms or electrical cables couldalso be shown with longitudinal section as in the invention which couldbe designed other than those explained above depending on therequirements or application concerned. In theory, the longitudinalelements could also be made with a casing of one or more plastic layers.

FIG. 8 shows how the invention is used on a known net 80 made of helicalbent longitudinal elements 81, 82 which in turn are made ofhigh-strength fibers 84 and the metal casing 85 as shown. On the endside, these twisted pair longitudinal elements 81, 82 by loops 83 orconnected jointedly likewise with one another. At least two suchlongitudinal elements could also be provided as strands.

Preferably the hardness when using longitudinal elements 81, 82 selectedwith a filling layer such that the degree of attachment in the finishedlongitudinal element has a high lateral pressure strength so thesehelical-shaped longitudinal elements 81, 82 remain resistant to bendingeven under load.

As such nets and/or meshes are generally installed in mountainous areaswhere access is difficult, their weight savings offer considerableadvantages when transporting and installing them.

FIG. 9 shows a diagram of a catchment net 90 which is installed on amountain face for example and which can be used to catch falling stones,scree, wood or similar and/or avalanches.

This catchment net 90 is made of interlocking rings 97 in a manner whichis known in itself and held via carrying and/or retaining lines 92 andsupports 91 anchored to the ground. The retaining lines 92 arepreferably fitted with known braking elements 93 which absorb additionalenergy in an impact.

Interlocking rings 97 of catchment net 90 are each made of at least onewound wire-shaped longitudinal element 98 and are bound advantageouslyby clamps 97′ or the like gripping the respective rings.

According to the invention, these wound longitudinal elements 98 areeach made of a core of high-strength fibers 94 and a metal casing 99surrounding these as FIG. 10 shows.

This metal casing 99 is sealed by a welded seam 99′ continuously alonglongitudinal element 98. Preferably these welded seams 99′ are arrangedin the wound state of longitudinal element 98 on the inside of ring 57so they are under compression when fitted. Longitudinal elements 98 mayalso be welded together at their ends or provided with locks. Likewise,the metal casing could also be pre-formed as a tube into a ring in eachcase and the fibers introduced into this tube.

Such longitudinal elements as in the invention could also be used inretaining lines 92 and braking elements 93 made by known means.

FIG. 11 shows part of a mesh 40 which is composed of strands 41, 46arranged axially and laterally at certain distances to one another, thelatter being made of wound longitudinal elements 42, 43 in each case.This creates openings 46′ in the case of the one strand 46 at crossingpoints 47 between two longitudinal elements 48, 49 corresponding to themesh length through which strands 41 arranged at an angle thereto arerun, binding them together.

According to the invention, these longitudinal elements 42, 43 wound toform strands each comprise a core of high-strength fibers 44 and a metalcasing 45 around them.

Such ring nets, meshes or other types of net and/or mesh each made withthese longitudinal elements as in the invention are particularly suitedto securing slopes for protection, safety, aquaculture or architectureor similar. They can be used either to save weight and hence reducetransport costs and make them easier to install or to make nets andmeshes stronger and more usable.

FIG. 12 shows a further embodiment of a longitudinal element 16 which isdesigned similarly to that shown in FIG. 1 and to which the differencesbelow have been made.

According to the invention, this longitudinal element 16 comprises acore 12 of a plurality of high-strength fibers 11, a filling layer 18surrounding them, a composite layer 19 and a metal casing 15′surrounding the latter. Metal casing 15 is provided along itslongitudinal extent with welded seam 15′ for example.

This filling layer 18 surrounding fibers 11 consists preferably of aplastic, such as polyurethane which may be used as a foam or cast resin.Composite layer 19 which is an adhesive ensures that a more or lessflush joint is made between core 12 and filling layer 18 and metalcasing 15 and so creates a load-distributing force distribution of thetensile stress and/or load-bearing capacity on the core and the metalcasing of longitudinal element 16.

It is therefore advantageous if materials can be used for this fillinglayer 18 and/or composite layer 19 which are flexible, pressure stableand low shrinkage, depending on the application concerned so they meetoperating requirements. Such suitable materials are plastics,advantageously polyurethane or arathane, although other substances mayalso be used. If these longitudinal elements are exposed to highlyfluctuating temperatures when installed, the materials must also beheat- and cold-resistant.

A further requirement of this filling layer 18 and/or composite layer 19is that these as protection must have thermal insulation characteristicsso the high-strength fibers 11 are not weakened by being overheated oreven lose their tensile strength when metal casing 15 made as a tube iswelded.

In the course of the invention, such a longitudinal element 16 is madein such a way that the fibers 11 are first laid against one anotherand/or bundled and are surrounded by filling layer 18. The latter may bepressed on or applied as resin and attached thereto. Metal casing 15 iscut to length from a longitudinal plate or similar and composite layer19 and filling layer 18 as the case may be applied to its inside. It isthen bent around fibers 11 without any play between them and then madeby fixing welded seam 15′ at its ends to longitudinal element 16. Itmust be verified that the metal casing is gas- and water-impermeableonce made so the longitudinal elements remain permanently weatherproof.

Instead of this filling and composite layer, only one or the other couldbe used of course or more than just one layer in each case could beprovided if certain characteristics of the longitudinal element are tobe achieved. A thin separate layer of a thermal insulation material ofplastic could be embedded, for example.

It would also be possible that the filling and/or composite layer couldbe extended into the core between the fibers so the core holds togetherbetter.

The invention is shown sufficiently with the embodiments explainedabove; but it could also be illustrated by other variants.

The metal casing could also be glued at an overlap and/or at the face ofthe projecting end of the casing.

To detect damage- or fatigue-induced changes in the composite, anoptical or electrical measuring element may also be inserted in the coreor between the metal casing and the core to enable damage to be detectedby magnetic induction. On the other hand, magnetisable casing materialscould be used to use contemporary measurement methods (e.g. MRT) todetect damage.

1. A longitudinal element, in particular for a traction and/orsuspension means, which is produced with a core (12, 26, 27, 33, 34)with high-strength fibres (11, 28, 29, 36, 37) and a casing surroundingthis core, characterised in that this longitudinal element (13, 23, 24,31, 32) is produced at least from this at least one core (12, 26, 27,33, 34) and the surrounding casing is produced as a metal casing (15,25, 35, 38, 39), preferably made of steel.
 2. The longitudinal elementaccording to claim 1, characterised in that a preferably protective orload-bypassing filling layer (14), such as for example a gel and/or anadhesive, a bandage or a mixture thereof, is inserted between the core(12, 26, 27, 33, 34) and the metal casing (15, 25, 35, 38, 39) and/or inthe core of the respective longitudinal element (13, 23, 24, 31, 32). 3.The longitudinal element according to claim 1, wherein the longitudinalelement (16) is formed from a core (12) with a plurality ofhigh-strength fibres (11), from at least one filling layer (18)surrounding same, a composite layer (19) as well as from the metalcasing (15) surrounding the latter.
 4. The longitudinal elementaccording to claim 1, wherein the metal casing (15, 25, 35, 38, 39) isattached to the outer circumference of the core (12, 26, 27 23, 33, 34)such that a layer that is impermeable by gas, UV radiation and/or wateris formed for these fibres (11, 28, 29, 36, 37), wherein the metalcasing is provided with a specific bending strength or deflectionstrength.
 5. The longitudinal element according to claim 1, wherein atleast one metal tape placed around the core or wound around this core isprovided for the metal casing (15) which tape, when the margins overlapor abut against one another, is connected by welding, gluing or asimilar connection.
 6. The longitudinal element according to claim 1,wherein the high-strength fibres (11, 28, 29, 36, 37) each extendthrough the whole longitudinal element (13, 23, 24, 31, 32) in onepiece, and there have a straight, stranded or other type of course. 7.The longitudinal element according to claim 1, wherein the high-strengthfibres (11, 28, 29, 36, 37) are made of plastic, such as aramid, basalt,carbon and/or the like.
 8. The longitudinal element according to claim1, wherein the high-strength fibres (11, 28, 29, 36, 37) are produced atleast partly from steel fibres (steel cords) with a tensile strength ofpreferably more than 2,500 N/mm2.
 9. The longitudinal element accordingto claim 1, wherein the core (12, 26, 27 23, 33, 34) formed from thehigh-strength fibres (11, 28, 29, 36, 37) is measured with an outerdiameter preferably of 1.5 to 8 mm.
 10. The longitudinal elementaccording to claim 1, wherein the wall thickness of the metal casing(15, 25, 35, 38, 39) is preferably 0.1 to 1.0 mm and can be designed asa pipe.
 11. The longitudinal element according to claim 1, wherein themetal casing (15, 25, 35, 38) has a cylindrical or otherwise-shapedouter surface and covers the core with one or more layers.
 12. Thelongitudinal element according to claim 1, wherein an optical orelectrical measuring element is present in the core or between the metalcasing and the core, to recognise changes caused by damage and/orfatigue.
 13. The longitudinal element according to claim 1, wherein ateach of their two ends, the wire-shaped longitudinal elements (15, 25,35, 38, 98) are closed by a closing means in order for the high-strengthfibres therein to be protected in particular against moisture and water.14. The longitudinal element according to claim 1, wherein thelongitudinal element (23, 24, 31, 32) can be used for a traction and/orsuspension means, in particular a spiral rope, stranded rope or adouble-headed cord, wherein the traction or suspension means is producedpreferably entirely from these longitudinal elements.
 15. Thelongitudinal element according to claim 1, wherein the longitudinalelement (56, 64, 74) can be used for a traction and/or suspension means,in particular a telecommunications cable (50), an electrical cable (60,70) or a cable with integrated electrical lines, wherein preferably anumber of longitudinal elements (56, 64, 74) are integrated in thetraction or suspension means or are arranged in strands around theoutside thereof.
 16. The longitudinal element according to claim 1,wherein the longitudinal element (81, 82, 98) can be used for a tractionand/or suspension means, in particular a web (80, 90), preferably forthe protection, security, aquaculture or architecture field, wherein theweb (80, 90) is produced preferably entirely from these longitudinalelements (81, 82, 98).
 17. The longitudinal element according to claim16, characterised in that the web (90) is composed of interlocking rings(97), wherein these rings (97) are each produced from at least onewire-shaped longitudinal element (98) wound multiple times with a core(99) made of high-strength fibres (94) and a metal casing (99).
 18. Thelongitudinal element according to claim 17, characterised in that themetal casings (99) are each arranged with a weld seam (99′) continuouslyalong the wound longitudinal element (98) on the inner side of the ring(97).
 19. The longitudinal element according to claim 16, characterisedin that the web is produced as a network (80) which is braided fromindividual longitudinal elements (81, 82) or folds of helically-curvedlongitudinal elements (81, 82).
 20. The longitudinal element accordingto claim 1, wherein the longitudinal element (42, 43) can be used for atraction or suspension means, in particular a grid (40), preferably forthe protection, security, armour or architecture field, wherein the gridis produced preferably entirely from these longitudinal elements (42,43).
 21. The longitudinal element according to claim 1, wherein eachlongitudinal element (13, 23, 24, 31, 32) is provided with around-shaped, Z-shaped, I-shaped, wedge-shaped or otherwise-shapedcross-section.
 22. The longitudinal element according to claim 1,wherein the metal casing (15, 25, 35, 38, 39), preferably the insidethereof, and/or the core, are surface-roughened.